The Plasma Plus Gravity Universe May Not Need Dark Matter

Under particular conditions, the experimental plasma spirals rotate as rigid bodies or are stationary with respect to the experimental apparatus and appear to be persistent. However, the velocity distribution for particles in the arms is not known. We suggest that an experimental determination of particle velocity distribution be made to compare with that of spiral galaxies. Because galaxies are composed largely of plasma, the assumption of dark matter should not be accepted by default without testing whether a plasma mechanism arising from electromagnetic effects could also be a possible explanation for the observed anomalies. If both the morphology and particle velocity distribution of spiral arms can be reproduced experimentally and mathematically, the need to postulate the existence of dark matter, which cannot be detected directly, would be obviated.